In recent years, personal computers have been widely used in a multimedia information society, and accordingly the demand for printers has been increased.
In particular, ink jet printers are low in price and capable of high-quality color print, so that their market has been growing rapidly.
The ink jet printers are available in various systems: a system in which a mechanical vibrating force is converted into pressure waves of ink by using a piezoelectric element and thereby ink droplets are discharged, a system in which bubbles are produced by suddenly heating ink and thereby ink droplets are discharged by the pressure waves of bubbles, a system in which ink is sucked and allowed to fly by an electrostatic force, and so on. Among these systems, the system using a piezoelectric element has received special attention because the manufacturing method of piezoelectric elements has advanced.
The following is a description of a conventional ink jet printing head using a piezoelectric element.
FIG. 12 shows a configuration of a conventional ink jet printing head using a piezoelectric element, which has been disclosed in Japanese Patent Application Laid-Open No. 6-40030.
FIG. 12(a) is a sectional view, and FIG. 12(b) is a top view. In these figures, reference numeral 101 denotes a nozzle plate, 102 denotes a flow path plate, and 103 denotes an orifice plate. These elements are joined with an adhesive to form an ink nozzle portion 110.
Also, reference numeral 104 denotes a connection plate, 105 denotes a spacer plate, and 106 denotes a closure plate. These elements form an ink pump portion 111 by integrally firing materials fabricated in a green sheet state in three layers.
On top of the ink pump portion 111, a piezoelectric/electrostrictive material 108 provided with electrodes 107 and 109 is formed by printing and firing.
In the ink jet printing head thus configured, ink is caused to flow through an ink supply path 113, an ink supply flow path 114 and a pressure chamber 115 are filled with ink, and ink droplets are discharged through nozzles 116 by the vibration of piezoelectric/electrostrictive element 108 caused by a predetermined electrical signal.
For such a conventional configuration, however, in arranging the nozzles 116 with high density, there is a technical limitation in minute fabrication of the spacer plate 105 and minute formation of piezoelectric/electrostrictive element 108 and the electrodes 107 and 109 by printing etc. Thereupon, the conventional configuration has a problem in that it is very difficult to produce a multi-nozzle head having a nozzle arrangement of high resolution such as 8 nozzles/mm or 16 nozzles/mm.
Further, many flat-plate members with different patterns, that is, 9-layer members with different patterns including the electrodes must be fabricated, formed, and laminated, which presents a problem in that the manufacture is complicated.